This invention relates generally to lamp post bases, and particularly to precast type lamp posts adapted to support relatively large outdoor lamps along streets and highways, in automobile parking lots, and the like.
Precast bases have heretofore been devised for supporting outdoor lamps, telephone and power transmission lines as exemplified by U.S. Pat. Nos. 1,624,237, 2,374,624 and 3,343,322. The precasting of such bases at manufacturing plants is substantially less expensive and time consuming than forming the support foundations on site. In using precast bases trench linked holes are formed in the supporting terrain by use of truckborne arbors or mobile post hole diggers. Electrical wiring is then laid in the trenches and guided through openings in the bases which are then seated in the holes and the terrain compacted laterally thereabout. The lamps are electrically connected to the wiring protruding out the tops of the bases. The lamp posts are then bolted to the tops of the bases at a point either flush with the surrounding terrain or elevated thereabove to prevent damage from being incurred by automobiles bumping into the posts themselves.
Though lamp post bases of the prior art have provided a distinct improvement over those of the type previously cast in situ, several problems associated with their use have remained. Chief among these problems has been the difficulty in quickly and efficiently forming holes in the terrain into which the bases may be snugly set without need for substantial repacking of the terrain or conversely, extracting additional earth from the holes which may have crumbled into the center thereof during digging. In addition, arbors typically supported upon trucks used in digging post holes and the like have usually not formed holes compatible in size to that required for setting lamp post bases. Yet another persistent problem has been the dilemma encountered in balancing bore strength with weight specifications. Substantially solid lamp post base construction offers high rigidity and immobility due to their mass but their weight renders them unwieldy and costly to produce and to channel electrical wiring therethrough.
Accordingly, it is a general object of the present invention to provide an improved lamp post base.
More specifically, it is an object of the present invention to provide a precast lamp post base which may be installed in supporting terrain with facility and efficiency.
Another object of the invention is to provide a relatively light weight precast lamp post base which may be set snugly in terrain holes having varying amounts of residual loose earth in the bottom thereof with uniform vertical positioning of the base during the setting operation.
Yet another object of the invention is to provide a lamp post base to which electrical wires may be routed with facility.